1. Field of the Invention
The invention relates to a trailer for transporting a vessel.
2. Background Art
A trailer intended to create a slipway is known from U.S. Pat. No. 4,286,346. This trailer comprises a wheel axle frame and a boat supporting frame which is connected to a rear side of the wheel axle frame so as to be hingeable, but not slidable or mobile. An end of the boat supporting frame remote from the wheel axle frame is provided with a telescopically slidable frame extension piece. At the end of this frame extension piece, floats are mounted. Placed on the boat supporting frame is a movable keel table on which the vessel rests. To launch the vessel, the telescopic extension frame is slid out first. Subsequently, the mobile keel table is gradually moved backwards. After some time, the boat supporting frame tilts until the floats float in the water. The keel table is then moved further backwards over the boat supporting frame and the frame extension piece, so that the stern of the vessel comes to float in the water. To launch the vessel further, the floating bodies are emptied so that the boat supporting frame can tilt even further until the boat is completely in the water. An advantage of this trailer is that it enables bridging a difference in height between the water surface and the land surface on which the trailer is situated. A drawback of this trailer is that the tilting occur very suddenly when the keel table is moved backwards and will further end very abruptly when the floats touch the water. This sudden tilting is dangerous to bystanders. The abrupt ending of the tilting can lead to damage to the vessel and the trailer. Another drawback of this trailer is further that it is not designed to pull a vessel situated in the water out of the water. The fact is that this publication is silent as to how the vessel can be brought from the water onto the keel table of the trailer. Furthermore, the use of a telescopic extension mechanism is disadvantageous because it is a relatively weak mechanism, which is therefore hardly capable of supporting the weight of the vessel. This drawback is partly compensated by designing the keel table relatively long, which is also necessary to stably support the whole boat. As a result of this considerable length of the keel table, the effective length of the boat supporting frame over which the keel table can be moved is, however, limited. Moreover, the effective length of the slipway is limited because for launching this whole, relatively long table needs to be brought under the floating level of the vessel. Furthermore, this publication does not indicate a provision stabilizing the vessel sidewards in the case of a part of the vessel already being in a floating position. It is to be noted that by the term slipway is meant the way over which a vessel can be set into the water and can be pulled out of the water.
German patent 529,516 discloses a trailer comprising a relatively long wheel axle frame comprising guides and a keel support movably arranged thereon. Placed on the keel support is a movable stem support. In use, the wheel axle frame is arranged on the shore in an inclined position, such that it forms an artificial slipway. Subsequently, the keel support is moved with the vessel to the water by moving the keel support over the wheel axle frame, during which the keel support slides out of the wheel axle frame. The stem support movable over the keel support only serves to move the boat over the keel support to the water over half a boat length. A drawback of this trailer is that only a slipway of a relatively small length can be supplied therewith. This length comprises at most three quarters of the boat length when the keel table is in the extreme position. Another drawback is that the trailer can only be used when the wheel axle frame, in the tilted position, rests the shore bottom. Because the trailer is not provided with floats, it is not suitable for use on any quay.
British patent 372,172 discloses a trailer provided with a wheel axle frame to which a boat supporting frame is connected so as to be hingeable, but not slidable or mobile. In use, an artificial slipway can be obtained with thin trailer through the hinging of the boat supporting frame relative to the wheel axle frame. A drawback of this equipment is that the length of the thus obtained slipway is at most half a boat length. Therefore, this trailer can only be used in a limited number of situations. Moreover, the position of the wheels of the trailer is such that, in use, only half of the boat supporting frame can extend from the wheel axle frame to the water. Therefore, this trailer can only used if the distance between the ground level on which the trailer is situated and the water surface of the launching water is very small. Since, moreover, floating bodies are lacking, launching is only possible on so-called stationary slipways especially arranged in the shore.
U.S. Pat. No. 3,140,003 discloses a trailer for moving a vessel provided with a telescopically slidable wheel axle frame. Mounted on the telescopically slidable part of the wheel axle frame are fixed keel supports on which the boat can rest with its keel. The known trailer will have to be of relatively heavy design because both the fixed and the slidable part of the wheel axle frame must be able to support the full weight of the vessel. Another drawback of this trailer is that a vessel cannot be set into relatively deep water therewith, because during the loading and unloading of a vessel the end of the boat supporting frame needs support from a fixed bottom and is not provided with floats
It is an object of the present invention to remove the above drawbacks. It is therefore an object of the invention to provide a trailer suitable and intended for being towed by a passenger car, s.u.v. or the like, by means of which a vessel can be set into the water and can be pulled out of the water without using a slipway especially constructed for the purpose, which trailer tan be used to bridge different, relatively great distances and/or differences in height between the shore or quay and the water surface. Here, the trailer must also be able to be of light design, but has great stiffness,
To this end, the trailer according to the invention is characterized by the features according to claim 1.
The rigid boat supporting frame is, in use, moved with a vessel along the guide elements from the wheel axle frame to the water to set the vessel into the water, or moved in reverse direction to pull the vessel out of the water. Because the boat supporting frame is of rigid design and is connected with the wheel axle frame, the guide elements can be of light design. The fact is that the risk of the guide elements bending too much is very low, because a substantial part of the weight of the vessel is transferred by the rigid boat supporting frame to the wheel ale frame and because the guide elements are clamped by guide means connected wit the rigid boat supporting frame, which guide means are connected with the boat supporting frame in different positions of the boat supporting frame. Therefore, the parts of the guide elements extending along the boat supporting frame will hardly, if at all, bend. In use, the major part of the boat supporting frame can extend from the wheel axle frame to the water, so that a very long, but yet very rigid slipway of at least one boat length, preferably almost the whole trailer length, is obtained therewith. This is advantageous if a relatively great launching height and/or launching distance need to be bridged. Furthermore, with this trailer a vessel with a relatively great draught, such as, a sailing boat with a fixed keel, can be simply launched without the keel making contact with a shore surface and/or the fixed bottom under the water. Since the trailer according to the invention is equipped with a separate hull support and stem or stern support, these can have a relatively short length, while yet a stable support of the vessel is realized. This has the result that a minimum length of the boat supporting frame is lost, and therefore a maximally long slipway is obtained. Since the boat supporting frame can extend over practically the whole length of the trailer (in the Netherlands the maximum length of a trailer is 12 m), for a trailer admitted under Netherlands law a slipway with a considerable length of about 11 m can be created.
An additional advantage is that the boat supporting frame can be moved relative to the wheel axle frame and relative to a vessel situated on the boat supporting frame. Consequently, the boat supporting frame can be situated, at least in the condition of transport, near a towing hook of a towing vehicle, while the vessel is placed at a greater distance from the towing vehicle. As a result thereof, even the distance required between the vessel and the vehicle so that bends can be taken, is utilized for storage of a part of the boat supporting frame. Consequently, the boat supporting frame can have an even greater length. Thus the trailer can be provided with a relatively long boat supporting frame, so that a relatively long slipway can be provided therewith. Furthermore, this trailer is very simple in use and can therefore be operated by only one person to set a vessel into the water or pull a vessel out of the water.
In use, the light guide elements are brought into the slid-out position and fixed relative to the wheel axle frame. In this initial situation, the boat supporting frame extends in a mainly horizontal transport position. Then the floats are connected with the free ends of the guide elements and filled with air or gas. Subsequently, the boat supporting frame is moved over the wheel axle frame in the direction of the floats of the guide elements. When the vessel is not yet situated at an end of the boat supporting frame, the boat supporting frame can also be moved under the vessel, while the position of the vessel is fixed relative to the wheel axle frame; only when the vessel has reached the of the boat supporting frame, the boat supporting frame and the vessel can be moved together further relative to the wheel axle frame. If available, the towing hook gripping frame is preferably coupled to a towing hook of a towing vehicle, which renders uncoupling operations superfluous and can effect gradual launching. The fact is that at a certain moment the center of gravity of the boat supporting frame and the vessel will be displaced relative to the wheel axle of the wheel axle frame such that the wheel axle frame comes to tilt about the wheel axle. The tilting is inhibited by the force exerted by the coupled towing vehicle on the wheel axle frame via the towing hook gripping frame. Consequently, this tilting will be effected very gradually, which is a great advantage of this trailer. If no towing hook frame is available and the towing hook coupling is connected with the boat supporting frame, the wheel axis frame, during launching, can be secured to the vessel with a number of lines or bands. Preferably, the trailer wheels are blocked during launching, for instance with their own brake or stop blocks, and the towing vehicle is gradually braked. Each time, the wheel axle frame, during a small further movement of the boat supporting frame relative to the wheel axle frame, will assume a new stable tilting position. When the boat supporting frame is moved further over a specific distance relative to wheel axle frame, the floats of the guide elements will touch the water surface and assume a floating position. In this situation, the wheel axle frame and the boat supporting frame cannot tilt any further, because the floats and the guide elements exert a counteracting moment on the boat supporting frame. Subsequently, the boat supporting frame can be moved completely in the direction of the floats, while the guide elements provide guidance and only to a limited extent experience a force from the weight of the vessel. In that situation, the freely projecting part of the guide elements subjected to a bending moment is already rather small, since the major part of the guide elements is already clamped by the guide elements fixed to the rigid boat supporting frame. Through this small length, bending will hardly, if at all, occur. Thus the guide elements are prevented from bending too far as a result of the weight of the vessel. When the end of the boat supporting frame proximal to the water has reached the floats, a stable, firm slipway has been realized. Subsequently, the vessel is moved to the water along the boat supporting frame by means of the stem or stern support and the hull support. The vessel is then only fixed to the above stern or stern support. When the vessel is completely in the water, it can be uncoupled from the stem or stern support, so that the launching is completed. To pull the vessel out of the water, the above steps must be carried out in reverse order.
Preferably, the floats are so designed through the degree of filling the floats with air or gas that the depth with which the boat supporting frame extends into the water during launching can be controlled. It is of special advantage if the form of the floats is of such design that, also when partly filled, these floats always assume a stable position in the water. To this end, the floats may have flexible walls. The height of the floater bags determines the maximum depth with which the end of the boat supporting frame proximal to the water can extend into the water. Thus the floats, for instance for some types of vessels, in particular keel boats, may have a height of 2 m, so that during setting into the water and pulling out of the water the vessel comes loose from the keel table, or can move with the keel to above the keel table he floats may be fixed to a float frame, which float frame is connected with the ends of the guide elements. The supply of air or gas to the floats may take place via the guide elements, preferably hollow design, and the float frame, preferably of hollow de sign.
According to a very advantageous elaboration of the invention the wheel axle frame supports a second wheel axe provided with wheels.
During the tilting of the wheel axle frame, the wheels of the second wheel axle frame exert an additional force, so that the tilting of the wheel axle frame can proceed extra gradually. The sides of the tires of the wheels, an optional suspension of the wheel axle frame and such elastically designed provisions may contribute to his. Furthermore, with a second wheel axle frame a better road behavior of the trailer can be obtained. Besides, the use of a second wheel axle frame is advantageous in connection with safety, for instance when one of the tires becomes leaky during transport of the vessel. Preferably, the second wheel axle frame is located near the first wheel axle frame, so that the wheels can properly cooperate with each other to allow the tilting of the wheel axle frame to proceed gradually and with a large number of intermediate positions in a wide angle range (typically 15xc2x0). The tilting may proceed over a relatively large angle.
According to a very advantageous elaboration of the invention the boat supporting frame comprises a box-frame-lattice construction provided with longitudinally extending tubes for moving the boat supporting frame along guide wheels of the wheel axle frame arranged for the purpose and for moving or guide the stem or stern support and the hull support thereover.
The above construction is very firm and very rigid. Moreover, such a construction can be of very light design without loss of firmness and rigidity. The construction is simply movable along the wheel axle frame, the stem or stern support and the hull support. By means of the guide wheels the movement can he controlled and carried out without failures.
According to a very advantageous elaboration of the invention the trailer is provided with wheels mountable to the free ends of the guide elements and/or the free end of the boat supporting frame.
The vessel may be very simply transferred from the trailer to the shore by using these wheels and by means of hull supports placed on the shore. To this end, the wheels are mounted to the free ends of the guide elements or the free end of the boat supporting frame, according to the guide elements used. The use of these guide elements is per se not necessary, because the tilting will proceed gradually, as will be discussed below. When the guide elements are used, they are then brought into the slid-out position and fixed relative to the wheel axle frame. Subsequently, the boat supporting frame is moved over the wheel axle frame in the direction of the mounted wheels. At a certain moment the center of gravity of the boat supporting frame and the vessel will be displaced relative to the wheel axle of the wheel axle frame such that the wheel axle frame gradually tilts about the wheel axle, as already discussed above. When the boat supporting frame is moved further relative to the wheel axle frame over a specific distance, the wheels mounted to the fee ends of the guide elements and/or the boat supporting frame will touch the ground surface of the shore. In this situation, the wheel axle frame and the boat supporting frame will not tilt any further, because the shore exerts a counteracting moment on the boat supporting frame. Subsequently, the boat supporting frame is moved completely in the direction of the mounted wheels. The vessel can then be moved over a distance along the boat supporting frame by means of the stem or stern support and the hull support in the direction of the mounted wheels, so that a stem or stern support of the vessel is brought closer to the ground surface of the shore. The vessel is only fixed to the stem or stern support. Subsequently, a first pair of hull supports is placed between a hull part of the vessel situated near the ground surface of the shore and the shore. Then the trailer is moved by a towing vehicle coupled thereto in a direction away from that first pair of hull supports, while the mounted wheels effect movement of the free ends of the guide elements or the free end of the boat supporting frame over the ground surface. This is advantageous, because thus damage to those ends is prevented. Furthermore, the movement of the trailer can smoothly, proceed by using these wheels. Through the movement of the trailer the first pair of hull supports placed between the shore and the vessel takes over a hull part of the vessel from the boat supporting frame. Thus the vessel is already on the shore with the first pair of hull supports. Because the stem or stern support is movable relative to the boat supporting frame, the boat supporting frame, during movement, will be moved under the vessel, while the stem or stern support moves over the boat supporting frame in the direction of the mounted wheels. The vessel rotates from an inclined position parallel to the boat supporting frame into a horizontal position. When the vessel is in the horizontal position, a second pair of hull supports is placed under the hull of the vessel on the shore. Then the vessel can be detached from the stem or stern support and the trailer can be driven off. Thus the vessel is placed on the above supports on the shore. The vessel can thus be very rapidly, stably and horizontally placed on the shore. When placing on the shore, the underside of the hull is easily accessible to carry out repair work. The stable placement farther provides safety to bystanders of the vessel. Furthermore, the empty trailer can be used to transport another vessel. To this end, the above steps can be taken in reverse order to transfer a vessel from the shore to the trailer.